kiss: Don't return from pkg_clean

This fixes an issue where a build failure alongside KISS_DEBUG
having a value of '1' prevented the package manager from aborting.

kiss

@@ -1295,8 +1295,7 @@ pkg_updates() {
 
 pkg_clean() {
     # Clean up on exit or error. This removes everything related to the build.
-    [ "$KISS_DEBUG" != 1 ] || return
-
+    [ "$KISS_DEBUG" = 1 ] || {
         # Create a list containing the current invocation's temporary files and
         # directories.
         set +f -- "$mak_dir" "$pkg_dir" "$tar_dir"
@@ -1308,6 +1307,7 @@ pkg_clean() {
         done
 
         rm -rf -- "$@"
+    }
 }
 
 args() {